显微组织对BT20钛合金应力松弛行为的影响

利用弯曲应力松弛方法研究了魏氏组织和等轴组织BT20钛合金的应力松弛行为和应力松弛过程中的塑性应变速率和应力的关系.研究表明,在200℃应力松弛的时候,BT20合金等轴组织具有较好的抗松弛性能;在400℃和600℃时BT20合金魏氏组织具有较好的抗松弛性能.     

1.4%C超高碳钢显微组织与疲劳性能的研究

对1．4％C超高碳钢试样热处理后的疲劳极限与断裂韧性进行测定，观察了显微组织与试样断口。结果表明，经950℃淬火700℃回火热处理后，又经860℃正火处理，试验用钢的组织结构超细化且碳化物弥散均匀分布，获得良好的综合强度与韧性及较高的疲劳极限，断裂强度较40CrNiMo调质态提高48％，屈服强度提高15％，延性指标相当，是一种优良的结构钢材料。     

EFFECT OF NaOH CONCENTRATION AND AlO_2~- SPECIES ON CAUSTIC STRESS CORROSION CRACKING OF A LOW ALLOY STEEL AT 260℃

用慢应变速率法（ＳＳＲＴ）、动电位扫描和循环伏安法研究１６ＭｎＲ钢在氧化铝溶出过程中的高温碱脆行为。结果表明，在２６０℃，１６ＭｎＲ钢的碱脆敏感性随ＮａＯＨ浓度（７．４２－１０．０６ｍｏｌ／Ｌ）的升高而增大；当碱液中含有ＡｌＯ２＾－离子时，１６ＭｎＲ钢的碱脆敏感电位区缩小，样品表面腐蚀产物保护性好，ＡｌＯ２＾－离子对低合金钢高温碱脆有一定抑制作用；１６ＭｎＲ钢在２６０℃碱液中生成的腐蚀产物为Ｆｅ３     

34CrMoA转子钢高温循环蠕变断口分形维数与蠕变性能的关系

用垂直剖面法测定了34CrMoA转子钢在550℃循环蠕变断口的分形维数,分析、比较了分形维数与蠕变性能的关系,结果表明,分形维数与断裂应变呈线性关系。     

晶界碳化物对Fe-Cr15-Ni25合金蠕变裂纹扩展行为的影响SCIEI

在两种不同晶界状态下研究了Fe-Cr15-Ni25合金的蠕变裂纹扩展行为。单相合金的空洞在晶界三叉点处形核,而对晶界上有碳化物析出的合金,空洞在晶界碳化物上形核。晶界碳化物阻碍了空洞的长大和连接,因而大大提高了蠕变裂纹扩展抗力。     

SOLUTION BEHAVIOUR OF VARIOUS ALLOYING ELEMENTS IN Ni_3Si

The solid solubilities of 15 common alloying elements added to the Ll_2-type intermetalliccompound Ni_3Si at 900°C have been estimated,and their substitution modes have been de-duced from the direction of solubility lobe of the compound.It is shown that the alloyingbehaviours in Ni_3Si are determined by both size and electronic factors,i.e.,the substitutionmode is governed by electronic configuration and solubility by the both.An interactionparameter is presented to describe quantitatively the influence of electronic configuration onsubstitution mode and the solubility limit can be successfully explained together with atom radius.     

CHARACTERISTICS OF INTERNAL FRICTION AND MODULUS ASSOCIATED WITH NON-EQUILIBRIUM DIFFUSION-TYPE PHASE TRANSFORMATION IN EUTECTOID Al-Zn ALLOY

The characteristics of the low frequency internal friction and the modulus effect associatedwith the non-equilibrium spinodal pretransformation and the following discontinuous trans-formation was investigated in an as-quenched eutectiod Al-Zn alloy.It was observed that theloss of the stability in the lattice,which corresponded to the large-amplitude long-wavelengthstatic concentration wave in the non-equilibrium spinodal pretransformation,did not induceany effect of localized soft modulus.Although there are two aging internal friction peaks inphase transformation which correspond to the appearance and disappearance of the coherencyin spinodal pretransformation and the maximum of the interface area in the discontinuoustransformation respectively,the effect of localized soft modulus did not take place yet.     

Zr,Cr和B对Ni3Al合金组织和力学性能的影响

本文研究了含Zr(0—0.6at.-％),Cr(0—7.7at.-％)和B(0—2.22at.-％)的Ni_3Al合金的组织和室温至1050℃拉伸性能。结果表明,Ni_3Al合金的屈服强度随温度升高而增加,表现出反常的温度关系。到达峰值后,随温度升高,屈服强度降低。Zr和Zr+Cr在整个试验温度范围都增加Ni_3Al合金的屈服强度,并改善高温抗张强度和塑性。硼增加Ni_3Al合金的抗张强度和屈服强度,同时改善塑性。但当硼含量超过1.37at.-％时,则降低强度和塑性。当硼含量超过溶解度极限时,Ni_3Al合金中形成岛状和球状的Ni_(20)Al_3B_6和Ni_3Al的共晶组织,对强度和塑性都是有害的。     

CLS AND AES STUDIES OF OXYGEN ADSORPTION AND INITIAL OXIDATION ON CLEAN In SURFACE

<正> 近年来对Al的氧吸附和氧化已有大量研究,相比之下,对较重的三价金属In的氧吸附研究甚少.本文用CLS(特征能量损失谱)和AES(Auger电子谱)研究了氧在In表面的吸附及氧化.实验在ESCALAB-5型电子谱仪上进行.